Explaining high oil prices

The U.S. economy is limping along, unemployment is still high, and gasoline demand for this time of year is at its lowest since the 1990s. So why does a barrel of domestic crude cost around $100?
Nymex crude futures have been on a tear lately, soaring 35% from the beginning of October to their recent peak in mid-November, and have crossed the $100-a-barrel threshold a handful of times………………………………………..Full Article: Source